The period of rest that was supposed to last 10 days ended at just five as Duncan pinch-hit in the Cardinals' 3-2 loss on Saturday afternoon in the first game of a doubleheader against the Cubs.
Duncan entered the game with nobody on and two outs in the ninth to face Cubs closer Ryan Dempster. Duncan worked the count to 2-2 before he struck out swinging.
"He could swing. If he got the ball in the outfield, he [could] get to first base without hurting himself," La Russa said. "That's all he was going to do."
Before the game, Duncan took batting practice on the field and took some additional hacks in the batting cages. At that point, La Russa didn't know what Duncan's availability for the game was, but La Russa said he saw enough from Duncan to let him have one at-bat.
Duncan's name was not listed with Skip Schumaker, Russell Branyan and Rick Ankiel as an available left-handed hitter on La Russa's lineup before the game, but that didn't stop the manager from using him.
Before his pinch-hitting appearance, the left fielder last appeared in a game on Sunday against the D-backs. He was used as a pinch-hitter in that game as well and struck out.
Eckstein's availability: Shortstop David Eckstein was not in the lineup for the first game of Saturday's doubleheader.
Eckstein is still nursing a sore lower back. It caused him to miss Friday night's game, and La Russa was unsure of Eckstein's availability for the twin bill against the Cubs.
"I have my doubts that he'll he available at all [on Saturday]," La Russa said. "He was still pretty sore this morning, so we'll just see how he's feeling."
After the first game of the twin bill against the Cubs, La Russa said he didn't expect to see Eckstein at all in the second game, either. The skipper was unsure of his shortstop's status for Sunday's series finale.
For the second straight day, Eckstein did not take batting practice or field ground balls with the team. Rather, he was inside receiving treatment for the soreness.
Clutch Ludwick: When Ryan Ludwick hammered a solo home run in the ninth inning on Friday night, it marked the sixth time this season Ludwick has homered coming off the bench.
Since being called up from Triple-A Memphis in early May, Ludwick has been one of the more dependable players on La Russa's bench. In games he doesn't start, Ludwick is sporting a .309 average with six homers and 10 RBIs.
The .309 average is more than 50 points higher than his season average of .255.
"He's very smart about being ready at the right time," La Russa said. "He's got clutch ability. You have to pay attention the whole game, and if the situation doesn't arise, you can't get frustrated. There is a lot that goes into it."
Ludwick credits some help he got from teammate Aaron Miles. When Ludwick was called up, it was first time playing with National League rules, after spending parts of four seasons in the American League with the Rangers and Indians.
"The first two weeks I was here, he would always come up and tap me on the shoulder and say, "Luddy, let's go hit. You might get in there,'" Ludwick said. "I wasn't real used to the National League game when I first came up. He's taught me so much about the double switch and knowing when to get in the cage and being ready for a pinch-hitting opportunity."
Ludwick also leads the team with two walk-off hits. One was a homer in the 14th inning against the Royals, and the other came via a single in the first game of a doubleheader against the Brewers in July.
"I've had kind of a knack for it this year, and it's been nice to contribute," Ludwick said.
The outfielder said he usually heads to the cages during the fourth or fifth inning and takes some swings with other players on the bench. He also rides the bike to get loose.
Gifts galore: On the chair of every player in the Cardinals clubhouse on Saturday was a gift from slugger Albert Pujols. Pujols got the whole team golf shirts from the 2007 All-Star Game in San Francisco. The former MVP was still awaiting the shirts for the coaches.
Baby 'Birds: The Springfield Cardinals dropped Game 3 of the Texas League Championship Series, 3-2, to San Antonio on Friday night at home.
Springfield got a good outing from starter P.J Walters, who went seven innings, giving up three runs on six hits, but they couldn't muster much offense. Mark Hamilton hit a solo home run in the first, and Colby Rasmus added an RBI double in the seventh for the S-Cards' two runs.
Springfield is now down, 2-1, in the best-of-five series. The Cardinals will resume it, facing elimination, on Saturday night.
Coming up: The Cards and Cubs will finish their three-game series with a matinee on Sunday. Former Cardinals pitcher Jason Marquis will take the mound for the Cubs, while lefty Mark Mulder will get the nod for the Cards. First pitch is slated for 1:15 p.m. CT.
Daniel Berk is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.